What position will Feleti Mateo play? Who will replace Brent Tate at right centre - and who will partner that player on the wing?

How will the front row shape up with Steve Price gone and converted back rowers Ben Matulino and Jacob Lillyman in the propping rotation?

What will the pecking order be in a back row bristling with talent? Has Shaun Berrigan still got it?

And who, out of the clutch of rising stars promoted from last year's champion NYC team, will handle the step up to the top grade?

These are the questions the Warriors will be out to answer over a four-match trials campaign that begins with a Miners' Solidarity charity match in Greymouth against the Newcastle Knights today.

Most interest will centre on Mateo, one of the most devastating runners in the NRL, but a player who does not seem to have an obvious positional home in the Warriors squad.

Mateo would start at five-eighth today and then probably switch to back row, coach Ivan Cleary said.

For Mateo, it seems, the modern doctrine that numbers on shirts and traditional positions need not necessarily apply will come into play.

"He'll play a bit of six and a bit of back row, but I just want him to play how he plays best," Cleary said.

"I think it going to be one of those things where he might move around a bit during the year but he will be playing the same style of football."

That probably means Mateo getting his hands on the ball at first or second receiver and using his powerful frame to break the line and release teammates.

The Tongan captain has posted an impressive 30 try-assists over his 80-match NRL career, most coming at or through the line rather than from a pass before it.

Whether Mateo has the passing and kicking game to replace last year's breakthrough star James Maloney at five-eighth remains to be seen.

At this stage the club's major recruit projects as an impact player off the bench. It is a role for which there is no shortage of competition.

Captain Simon Mannering, vice-captain Michael Luck and last year's breakthrough forward Lewis Brown will be at the head of the queue for back row starting positions, with Ukuma Ta'I and Sione Lousi next.

Then come the likes of new recruit Steve Rapira and impressive youngsters Ben Henry, Matt Robinson and Elijah Taylor.

Throw Mateo into that mix and the Warriors have an embarrassment of back row riches.

"One thing I am confident about is that we have got some good depth there," Cleary said. "If we get a few injuries here or there we can cover for it."

Berrigan appears set to challenge incumbent Aaron Heremaia and backup Alehana Mara for the hooking jobs, although the former Queensland and Australia representative can also play centre.

"It's not a bad combination to have, and it's an unusual one," Cleary said. "That's one of the reasons we thought he'd be a good buy for us. He's very much a no-nonsense, low-maintenance kind of guy who has turned up in very good condition. It feels like he has been around for three months rather than three weeks."

Mateo's former Eels teammate Kristnan Inu and Joel Moon appear to have the most to play for in the trials.

Both are seeking the right centre berth vacated by Tate, although Inu's ability to play wing could team the pair on that flank.

"It will come down to performance and what looks the best mix throughout the trials," Cleary said.

Kevin Locke, Bill Tupou and star NYC fullback Glen Fisiiahi are the contenders for the right wing spot.

In the halves, Isaac John is close to a return from a knee reconstruction but won't play today, and Shaun Johnson is also out, with a back injury.

The club would have a close look at Vulcans halfback Pita Godinet, who had impressed in training, Cleary said.